[U-Boot] [U-Boot,8/8] rockchip: remove unused rk_timer.c

[Philipp Tomsich]

> All other SoCs have conver to use ARM arch timer or Rockchip DM timer,
> so we can remove rk_timer.c now.
> 
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> ---
> 
>  arch/arm/mach-rockchip/rk_timer.c | 48 ---------------------------------------
>  1 file changed, 48 deletions(-)
>  delete mode 100644 arch/arm/mach-rockchip/rk_timer.c
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>